routing spec
product api and spec
fix some test case
add products#bad_devices API
add report_date to device#health API
add Grape API helper module CommanHelper

- get_availabilities
- get_bad_devices
订正 idc product_tree API 支持 get_bad_devices & get_availabilities
add /api/devices/:sn/health/detail routes

- reduce system loads for /api/devices/:sn/health route
add get_bad_devices default filter :bad

and fix some bugs
增加 AvaComputable 对象的 bad_devices API, 修正 Device 的 health API

- 规范化 get_bad_devices & get_availabilities 方法到 API::CommonHelper
  module
- Device health API 默认不输出 monitor_reports 报告
- 增加 /api/devices/:sn/health/detail API 输出 monitor_reports